Shocking footage from a helmet camera video released by the Albuquerque Police Department (APD) shows the moment James Boyd turns his back on armed officers and is immediately shot dead.

Despite a raft of criticism the APD has said its officers were justified in killing the man.

Boyd, 38, was killed on March 16 after reportedly arguing with officers for over three hours.

After being surrounded by at least two armed men, and another man with an attack dog, Boyd seems to be preparing to leave but as he heads down the hill an officers screams "Do it," before a flash-bang device explodes.

SHOCKING: The Albuquerque Police Department has come in for criticism following the death of homeless man James Boyd [KRQE]

“F****** disgraceful! All those officers should be kicked off the police force immediately and jailed for that cold act”

An outraged YouTube user

Boyd then drops his bags and pulls out a knife before being shot multiple times by officers Dominque Perez and Keith Sandy.

Once he has been floored officers continue to yell at Boyd and the dog is set on him.

Blood can be seen near Boyd's head and he was taken to hospital and pronounced dead a day later.

"F****** disgraceful! All those officers should be kicked off the police force immediately and jailed for that cold act," wrote one YouTube user.

"He was barely armed and was walking away. If you can't judge a situation like that correctly then you don't deserve to wear a badge."

"I was a police officer for a decade," said Patrick Davis, executive director of ProgressNow, a citizens rights group in New Mexico.

"The over-militarised approach to law enforcement is having a very real effect on people's lives here in New Mexico and our leaders who should be taking real action seem to be taking it all in stride."

Albuquerque officers have shot more people than the NYPD, a department serving a city 16-times larger, since 2010, according to ProgressNow.

Officers Perez and Sandy have been placed on paid administrative leave.